1. Field of the Invention
The present invention relates to devices which are used for pulling large sheets of material, and more particularly to devices which are used for pulling water-proof membranes over flat roofs.
2. Description of the Prior Art
Buildings with flat tops often have roofs installed with a membrane-type material. This roofing material comes in sheets which are pulled across the flat top of the building. Since the roofing material is flexible and difficult to pull so that it is taut, the finished roof is normally quite wrinkled in appearance. While the wrinkling does not adversely affect the weatherability of the roof, it is considered aesthetically unacceptable by some customers.
One prior art roofing material puller was made for pulling this membrane-type roofing material. The device included a wooden base, a wooden lever pivotally attached to the base, and a cable fastened to the lever and extending through a grommet at the front end of the base, for guiding the cable. At the other end of the cable, the puller included a gripping member to grip the membrane. The roofing membrane was pulled by placing the front of the base facing the membrane, attaching the gripping member to the membrane, and then pulling the lever in a direction away from the membrane. The device could only be held in place by nailing to prevent the device from sliding forwardly on the roof when the membrane was being pulled. Since using this device required placing it with its front facing the membrane, the membrane could not be pulled all the way to the edge of the flat roof using this puller. The membrane could only be pulled up to the front of the base, where it was separated from the edge of the roof by a distance which was approximately equal to the length of the device's base.
Other devices have been developed for pulling sheet material such as carpets. For example, U.S. Pat. No. 1,971,218 to Hoobler discloses a carpet vice which includes gripping jaws connected to a tong-like apparatus. At the other end of the device are teeth which are intended to grip the floor as the carpet is pulled. An "L" shaped lever at its lower end engages slots in the device and is designed to be pulled toward the direction of the teeth, thereby pulling the carpet. Again, the lever action of this device is directed away from the carpet material which is being pulled, and requires that the front of the device face the carpet.
Other prior art pulling devices include those shown in U.S. Pat. Nos. 58,653 to Lindner, 498,977 to Harvey, and 2,665,884 to Martin.